Cement spray gun with remote air injection

ABSTRACT

A spray gun for cement or the like material which includes a substantially cylindrical gun having a nozzle at one end thereof and a hose connected to the other end thereof. Handle means will be provided for manually supporting the gun in position during use. The other end of the hose is connected to a supply of liquid cement or the like material. Air under pressure is introduced into the hose adjacent the supply, the angle of introduction of the air being inclined in a forward direction and also substantially tangentially so as to provide a swirling action within the hose.

United States Patent [1 1 Kellert [451 Mar. 18, 1975 CEMENT SPRAY GUN WITH REMOTE AIR INJECTION [76] Inventor: Paul 111. Keller-t, RR. 1, Mannford,

Okla. 74044 [22] Filed: Dec. 29, 1969 [21] Appl. No.: 888,620

[52] 11.8. CI 239/302, 239/403, 222/193, 259/151, 302/63 [51] Int. Cl. B05b 7/26 [58] Field of Search 302/24, 63; 222/193; 239/403, 405, 302; 250/151 [56] References Cited UNITED STATES PATENTS 1,039,958 10/1912 Kimball 302/24 1,670,677 5/1928 Brown 259/151 1,902,202 3/1933 Vawter 3,212,759 10/1965 Brown 259/151 R24,716 10/1959 Anselman et a1. 302/24 CEMENT FOREIGN PATENTS OR APPLICATIONS 1,146,519 3/1969 United Kingdom 302/24 Primary E.\'aminerLloyd L. King Assistant Examiner-1ohn J. Love Attorney, Agent, or Firm-Williarn S. Dorman [57] ABSTRACT A spray gun for cement or the like material which includes a substantially cylindrical gun having a nozzle at one end thereof and a hose connected to the other end thereof. Handle means will be provided for manually supporting the gun in position during use. The other end of the hose is connected to a supply of liquid cement or the like material. Air under pressure is introduced into the hose adjacent the supply, the angle of introduction of the air being inclined in a forward direction and also substantially tangentially so as to provide a swirling action within the hose.

2 Claims, 2 Drawing Figures PATENTED 3871.583

F'IG. i

o 9 E m a w J INVENTOR. 5 P H. KELLERT 4 DJ ATTORME Y CEMENT SPRAY GUN WITH REMOTE AIR INJECTION The present invention relates to a spray gun for cement or the like material including a substantially cylindrical gun having a nozzle at one end thereof and a hose connecting from the other end of the nozzle to a source of supply of liquid cement or the like material. More particularly, the present invention relates to the injection of air at a point adjacent the supply at a forward and tangential angle with respect to the hose.

It is well known in the art to spray cement from a spray gun. It is also conventional to use air or gas under pressure to force the liquid cement from the spray gun. However, the prior art generally teaches the introduction of air directly to the gun itself.

The present invention, on the other hand involves the introduction of air (or other gas) under pressure into the hose at a point remote from the gun or, stated differently, at a location adjacent the source of supply of liquid cement. Furthermore, the air is introduced at a forwardly directed angle which tends to force the cement in a direction towards the gun. Secondly, the air is introduced into the interior of the hose tangentially with respect to the cross sectional area of the hose. Preferably, the air is introduced through two conduits which are staggered slightly longitudinally with respect to each other and, with respect to the cross section of the hose, substantially diametrically opposite each other. The effect of the foregoing air injection is to break up the material more completely by literally bouncing the material in a circular motion in the rear portion of the hose; this provides a more uniform flow through the nozzle. Furthermore, the introduction of the air at the far end of the hose prevents the liquid slurry from heating up in the hose, thereby retarding the initial set ofthe cement and leading to an improved and more rapid flow through the nozzle.

Therefore, it is a principle object of the present invention to provide a spray gun for cement or the like material which includes a substantially cylindrical gun having a nozzle at one end thereof and a hose connected from the other end of the gun to a source of sup ply of liquid cement or the like material, air or gas under pressure being introduced into the hose at a location remote from the spray gun.

It is a further object of the present invention to provide a spray gun for cement as described above wherein the air is introduced into the hose at a point adjacent the supply in a forwardly directed angle and tangentially with respect to the cross sectional area of the hose.

It is a further object of the present invention to provide a spray gun of the type described above wherein the air is introduced at two points which are slightly staggered with respect to each other in the longitudinal direction at diametrically opposite sides of the hose.

Other and further objects and advantageous features of the present invention will hereinafter more fully appear in connection with a detailed description of the drawings in which:

FIG. 1 is an elevation of the spray gun hose and air injection chamber with certain parts broken away for ease of illustration; and

FIG. 2 is a transverse cross sectional view through the air injection chamber along the section line 2-2 of FIG. 1.

Referring to the drawings in detail, FIG. I shows a spray gun 10 having a nozzle 12 and handles 14. The nozzle 12 is preferably threadedly connected to the gun 10 so that it can be replaced with a like nozzle having a different orifice opening as desired. A hose 16 which is flexible and which is preferably made out of reinforced rubber or the like is connected to the gun I0 by means of the threaded coupling 18. The other end of the hose 16 connects with an air injection chamber 20 by means ofa threaded coupling 22. Although the hose I6 is broken and shows a relatively small longitudinal extent, it should be understood that this hose could be fifty feet or more in length. The air injection chamber 20 is nothing more than a length of pipe made of steel or cast iron or other suitable material having substantially the same internal diameter as the hose l6 and, in a sense, can be considered as the rear portion of the hose 16. The only reason that the section 20 is made out of metal is that it is easier to connect the air inlet pipes 24 and 26 to the metal pipe 20 than it would be to attach them to the hose 16. The left hand end 28 of the chamber 20 connects with a source of supply 30 of liquid cement or the like.

As will appear from a consideration of FIG. I, the pipe 24 is connected to the mixing chamber 20 at a forward angle; i.e. as air is introduced into the chamber 20 through the pipe 24 it will tend to force any material in the chamber 20 towards the right. Similarly, the air injection pipe 26 is also inclined in a forward direction for the same reason.

From a consideration of FIG. 2, it will appear that the air entering the chamber 20 from the pipes 24 and 26 will enter tangentially thereby tending to move the material in a generally circular direction. Thus the air injection will move the liquid slurry both forwardly and in a circular direction. The air jets also tend to break the material up more completely. Finally, the air will tend to evaporate some of the water from the slurry thereby cooling the mixture so as to retard the initial set of the cement as it flows through the hose towards the nozzle. The ultimate effect is a more uniform and more rapid flow of cement from the nozzle 12 of the gun.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention. For example, although it is indicated heretofore that the hose can be fifty feet or more in length, in practice the hose is generally a hundred feet or more in length. If it is desired to use even longer lengths of hose, and if it should appear in this connection that the flow rate at the nozzle is less than that desired, then additional air injection devices such as shown in FIG. 1 can be introduced into the line as desired, preferably at points about one hundred fifty feet or more apart.

What is claimed is:

1. Apparatus for conveying liquid cement through a conduit from a supply of liquid cement to a discharge nozzle comprising a substantially cylindrical gun having an inlet end and a discharge end, said gun having a nozzle at the discharge end thereof; a cylindrical flexible hose having an inlet end and a discharge end, the dis charge end of said hose being connected to the inlet end of said gun; a source of supply of liquid cement; a cylindrical and metallic air injection chamber having one end connected to the inlet end of said hose and having an opposite end connected to said source of supply of liquid cement, said air injection chamber having substantially the same internal diameter as said hose; and an air injection pipe connected at a forwardly directed angle to said air injection chamber for introducing air under pressure into said chamber at a forwardly directed angle, said air injection pipe being also connected tangentially with respect to said chamber so as to introduce said air tangentially with respect to the cross sectional are of said chamber.

2. Apparatus as set forth in claim 1 including a secber. 

1. Apparatus for conveying liquid cement through a conduit from a supply of liquid cement to a discharge nozzle comprising a substantially cylindrical gun having an inlet end and a discharge end, said gun having a nozzle at the discharge end thereof; a cylindrical flexible hose having an inlet end and a discharge end, the discharge end of said hose being connected to the inlet end of said gun; a source of supply of liquid cement; a cylindrical and metallic air injection chamber hAving one end connected to the inlet end of said hose and having an opposite end connected to said source of supply of liquid cement, said air injection chamber having substantially the same internal diameter as said hose; and an air injection pipe connected at a forwardly directed angle to said air injection chamber for introducing air under pressure into said chamber at a forwardly directed angle, said air injection pipe being also connected tangentially with respect to said chamber so as to introduce said air tangentially with respect to the cross sectional are of said chamber.
 2. Apparatus as set forth in claim 1 including a second air injection pipe connected at a forwardly directed angle to said air injection chamber at a position diametrically opposite from and longitudinally spaced from the point of connection of said first-mentioned air injection pipe to said chamber for introducing additional air under pressure into said chamber at a forwardly directed angle, said second air injection pipe being also connected tangentially with respect to said chamber so that both pipes introduce air tangentially with respect to the cross sectional area of said chamber. 